This invention relates generally to packaging and more particularly to flexible packaging.
Flexible containers formed of sheet materials have gained wide acceptance in the trade for holding various products therein. Such packages commonly comprise two panels of flexible sheet material, e.g., polyethylene, polyvinylchloride, polyester, etc., which are heat sealed to each other along their periphery to form a sealed chamber in which the packaged product is located.
It has been proposed by a potential customer of the assignee of this invention to construct a package for receipt of a stack of light sensitive film sheets (e.g., X-ray film), to enable individual sheets to be removed from the package for exposure and processing. Owing to the light sensitive nature of the sheet material it is necessary that the package be formed of a material which is light-tight. Various light-blocking flexible materials are commercially available for formation into a package for holding light sensitive materials to prevent ambient light from damaging the materials. The package construction proposed to the applicants' assignee included a base formed of a light-blocking plastic material defining a recess or cavity in which sheets of the light sensitive materials would be disposed. The cavity with the light sensitive materials was to be covered by a pair of panels of light-blocking plastic material to prevent ambient light from reaching those materials. A first of the cover panels was proposed to be permanently secured to the package's base along the cover panel's peripheral edges. The second cover panel was proposed to be permanently secured to the base along one of its peripheral edges while being releasably secured to the base and the first cover panel via a peelable seal along other of its peripheral edges so it could be peeled full back from the first cover panel and partially back from the base to form an access mouth for the light sensitive sheets within the package.
The foregoing package, while apparently generally suitable for its intended purposes, nevertheless is deemed by applicants herein to leave something to be desired from the standpoints of simplicity of construction and effectiveness or efficiency of use. Accordingly, it is believed that a need presently exists for an inexpensive, completely flexible package, formed of a light blocking material, which is readily sealable to store light sensitive materials therein, yet which includes a cover panel which can be readily peeled completely away from the package to provide access to the light sensitive materials stored within the package.